This invention pertains to a method of printing a print pattern by transferring it on a transfer objective body having a three-dimensional surface such as a curved surface or the like by using a liquid pressure on an objective article (a body onto which the print pattern should be transferred) and more particularly, this invention pertains to a method of transferring the predetermined print pattern by using the liquid pressure on the transfer objective body having a relatively larger transfer face area such as a fender, a door, a bonnet or the like of a car, for example.
Furthermore, this invention pertains to an apparatus useful for practicing the aforementioned method and also to a liquid pressure pattern-transferred article formed by the aforementioned method.
A so-called liquid pressure transfer method has been used for printing various patterns onto a transfer objective body or article having a complicated surface configuration. Typically, this liquid pressure transfer method is one in which a liquid-soluble pattern transfer film having a predetermined print pattern of no liquid solution provided thereon is floated on a surface of a liquid flowing within a transfer bath and is made swollen by the liquid and then the transfer objective body is immersed into the liquid within the transfer bath while it contacts the transfer film and has the print pattern transferred from the transfer film by using a liquid pressure.
In a prior art, the transfer objective bodies are sequentially supported on a plurality of holding frames which are mounted on a reversely triangular conveyor in a spaced manner while the reversely triangular conveyor is disposed so that a conveyor portion adjacent to an underside apex of the triangular conveyor is immersed into the liquid. The reversely triangular conveyor conveys the transfer objective bodies so that each of the objective bodies contacts the liquid within the transfer bath just before or upstream of the underside apex conveyor portion going to be immersed into the liquid, is then immersed into the liquid and leaves the liquid on the opposite side or downstream of the underside apex conveyor portion whereby the pattern-transferred objective bodies are pulled out of the transfer bath (see U.S. Pat. No. 4,436,571 specification and Japanese patent Application Publication No. 13064/1991 (JP3-13064)).
According to the prior art, the transfer objective body is immersed into the liquid with the transfer bath at a constant velocity while it is held onto the reversely triangular conveyor with the same pose maintained. Thus, it will be noted that the condition in which the surface of the transfer objective body contacts the transfer film remarkably varies in accordance with variation in a three-dimensional configuration of the surface of the transfer objective body.
More particularly, many transfer objective bodies have a surface varying in a three-dimensionally complicated manner except to a plane article. If such a whole transfer objective body is immersed into the liquid by the conveyor with the same pose maintained, the relationship of position-between the individual portions of the transfer objective body being immersed into the liquid and the transfer film floating on the transfer bath remarkably varies on the surface configuration or profile of the transfer objective body.
In case that the transfer objective body is small-sized, a radius of curvature of the surface of the transfer objective body is relatively smaller and has a smaller area of the individual portions having the three-dimensional surface different from each other even though the surface configuration of the transfer objective body largely varies or is complicated whereby the three-dimensional configuration (a curvature, for example) mutually varies. Therefore, the print pattern is transferred onto such surface portions of the transfer objective body having the three-dimensional configuration different from each other without having such remarkable variation in appearance as adversely affects the transferred pattern.
However, in case that the print pattern on the transfer film is transferred onto a relatively larger body such as a car panel including a fender, a door, a bonnet, a bumper of a car or the like by using the liquid pressure transfer method, the radius of curvature of the individual surface portions having the three-dimensional configuration different from each other is larger and as a result, the area of the individual surface portions gets larger. As such a transfer objective body is immersed into the liquid with the same pose, the print pattern is transferred onto the individual surface portions on the conditions different from each other and as a result, the transferred pattern on the whole transfer objective body is made irregular whereby the appearance of the transfer objective body tends to be deteriorated.
This tendency gets remarkable particularly in case that the surface portion of the transfer objective body which is just going to be immersed into the liquid greatly protrudes toward the liquid surface or toward the side opposite thereto. More particularly, in case that the surface portion of the transfer objective body which is just going to be immersed into the liquid greatly protrudes toward the liquid surface (or dent on the side opposite to the transfer film), the print pattern on the transfer film is extended due to the protruding surface of the transfer objective body so that the pattern is distorted (deformed) or so that the thickness or density of the ink of the print pattern is lowered. Similarly, in case that the surface portion of the transfer objective body which is just going to be immersed into the liquid greatly dents on the side opposite to the transfer film (or protrudes toward the side opposite to the transferring film), the print pattern on the transfer film is extended due to the protruding surface of the transfer objective body so that the pattern is distorted (deformed) or so that the thickness of the ink of the print pattern is lowered. Thus, in both of the aforementioned cases, the transfer objective body cannot disadvantageously provide good appearance.
Generally, the transfer film has a transferring pattern painted while it extends in a uniform direction (such as in a longitudinal direction, for example). As the printed pattern is transferred onto the transfer objective body such as a fender of a car or the like having a surface curved in a curved line, but not extending in a rectilinear line in a longitudinal direction while being used together with other transfer objective body or bodies such as a door of the car or the like having a surface extending in a rectilinear line in a longitudinal direction, the patterns transferred onto these objective bodies get disunited. Thus, an article formed of a combination of these objective bodies has an extremely poor surface appearance.
A large-sized article such as a door panel of a car is sometimes required to have along an edge of a back face thereof the same transferred pattern as that on the surface thereof in a successive manner. Such an operation of transferring on the back face cannot be effectively made by the prior art in which the transfer objective body is immersed into the liquid with the same pose.
Accordingly, it is a principal object of the invention to provide a liquid pressure transfer method and an apparatus therefor adapted to provide satisfactory transfer characteristics having no deformation and no thinner color of a transferred pattern even though a transfer objective body onto has a large-sized and complicated surface configuration.
It is another object of the invention to provide a liquid pressure transfer method and an apparatus therefor adapted to apply onto a surface of a transfer objective body a transferred pattern extending in an appropriate direction even though the transfer objective body extends not along a linear line in a longitudinal direction, but along a complicated line such as a curved line.
It is another object of the invention to provide a liquid pressure transfer method and an apparatus therefor adapted to effectively apply a transferred pattern not only onto a surface of a transfer objective body, but also onto a back face succeeding the surface thereof.
It is another object of the invention to provide a liquid pressure transfer apparatus adapted to effectively apply a transferred pattern onto a transfer objective body having a large-sized and complicated configuration.
It is another object of the invention to provide a liquid pressure pattern-transferred article having a good appearance without making a transferred pattern unclear or without disarranging the transferred pattern relative to a direction in which the transfer objective body extends although it has a large sized and complicated configuration.
Firstly, this invention pertains to an improvement on a liquid pressure transfer method of transferring a print pattern on a transfer film floating on a surface of a liquid within a transfer bath by immersing a transfer objective body into the liquid while it is faced to the transfer film. This method may be of a transfer film feeding system in which the transfer film is fed on the surface of the liquid within the transfer bath at a given feeding velocity or of a transfer film stationary system in which the transfer film floats on the surface of the liquid within the transfer bath in a stationary manner while is placed on the liquid surface by a batch system. Since an activator is sprayed onto the transfer film on the surface of the liquid within the transfer bath by using a sprayer or the like so as to make an ink of the print pattern humid, the condition in which the ink on the transferred film is activated never varies on the area portions thereof and thus the area where the transfer objective body is immersed into the liquid may be set voluntarily.
A first method of the invention is to fundamentally immerse a transfer objective body into a liquid while a pose of the transfer objective body is controlled so that the transfer objective body contacts the surface of the transfer film following the transfer objective body whereby the surface of the transfer objective body onto which a print pattern should be transferred is developed on the surface of the transfer film in a plane manner relative thereto.
This can be ideally accomplished by supposing an imaginary development face on the transfer film within the transfer bath so as to be identical to a face obtained by developing in a plane manner the surface of the transfer objective body onto which the print pattern should be transferred and then immersing the transfer objective body into the liquid while the pose of the transfer objective body is so controlled that the surface of the transfer objective body follows the surface of the transfer film whereby the transfer surface of the transfer objective body is identical to the imaginary development on the transfer film. However, since it is difficult that the transfer surface of the transfer objective body follows the surface of the transfer film in the same manner as it does ideally, the transfer surface of the transfer objective body will practically follow the surface of the transfer film in the almost ideal condition.
In one embodiment of the invention, this can be accomplished by sequentially rolling on the surface of the transfer film the face of the transfer objective body onto which the print pattern should be transferred (which will be referred to as xe2x80x9ctransfer facexe2x80x9d, xe2x80x9cdecoration facexe2x80x9d or xe2x80x9cdesign facexe2x80x9d hereinafter) so that the transfer surface of the transfer objective body is substantially identical to the imaginary development face on the transfer film.
Rolling the transfer objective body may be made preferably in all radial directions of the transfer objective body, but as it tries to be made in all the radial directions, the pose of the transfer objective body when immersed will get complicated. Thus, in practice, rolling will be made along a central cross section in its longitudinal direction and its transverse direction for every large-sized surface portion of the transfer objective body forming the surface configuration of the transfer objective body just contacting the liquid.
A system of rolling the transfer objective body will effectively work in case that the transfer face of the transfer objective body (decoration face or design face) is only on the surface (front face) thereof, but in case that the transfer face of the transfer objective body is also on a back face, rolling will not work on this back transfer face.
Another embodiment of the invention described herein just below will effectively work for such a back transfer face. In this embodiment, the transfer objective body enters the liquid while it is lowered in such a condition as the surface of the transfer objective body is inclined and with one of the edges of the transfer objective body being directed toward the surface of the transfer film and thereafter it is immersed into the liquid while it is lowered obliquely downward with a such a pose as the transfer face of the transfer objective body contacts the transfer film while it follows the surface of the transfer film so that the surface of the transfer objective body is developed on the surface of the transfer film in a plane manner. As one of the edges is lowered and enters the liquid together with the transfer film, a portion of the transfer film succeeding the portion of the transfer film adhering to the surface of the transfer objective body is drawn closer to the edge of the back face of the transfer objective body so as to cover the edge of the back face until the print pattern on the transfer film is successively transferred on the surface and back face of the transfer objective body.
Thereafter, as the transfer objective body is lowered into the liquid obliquely downward while the transfer objective body is maintained in the inclined condition, the front transfer face of the transfer objective body enters the liquid while contacting the surface of the transfer film as if the front transfer face is developed in a plane manner on the surface of the transfer film portion succeeding the transfer film portion adhering to the back edge of the transfer objective body.
Thus, as the transfer objective body is developed on the transfer film by such a transfer objective body oblique lowering system, there can be provided the transfer objective body having a decoration faces succeeding on the front face and the back face of the transfer objective body.
In either of the transfer rolling system and the transfer objective body oblique lowering system, the transfer objective body is required to enter the liquid so that no air pocket is formed between the surface of the transfer objective body and the transfer film. This can be accomplished by an operation in which the transfer objective body enters the liquid without closing a dent possibly forming the air pocket. This can prevent air from being involved in the dent.
In case that the method of the invention is of a transfer film feeding system in which the transfer film is successively fed into the transfer bath, the transfer objective body should enter the liquid preferably at a position most suitable for transferring the print pattern with the transfer film perfectly activated within the transfer bath and then fully swollen by the liquid within the transfer bath. If the liquid entrance position of the transfer objective body is shifted on an upstream side in a direction of feeding the transfer film, the print pattern will be transferred in the condition in which the transfer film is not perfectly activated and the ink of the print pattern is not swollen, which causes undesirable pattern discontinuation and wrinkles of the transferred pattern to occur.
Also, in case that the method of the invention is of a transfer film feeding system in which the transfer film is successively fed into the transfer bath, the transfer objective body desirably enters the liquid so that the surface of the transfer objective body contacts the transfer film at a velocity corresponding to the feeding velocity of the transfer film.
However, in the invention, the liquid entrance velocity of the transfer objective body is not required to correspond to the feeding velocity of the transfer film in all cases, but in some cases, it may be later or earlier than the feeding velocity of the transfer film in accordance with liquid entrance conditions such as a liquid entrance angle of the transfer objective body or arbitrarily. Arbitrary variation in the liquid entrance velocity may be made in case that a color tone of the whole decoration face of the transfer objective body is required to vary or the pattern is required to be adjusted, for example.
Furthermore, the transfer face portion of the transfer objective body ideally enters the liquid while it follows the transfer film so as to be developed on the transfer film in a plane manner and it is also required to consider that no air is involved between the transfer objective body and the transfer film. To this end, an angle (liquid entrance angle) of the surface portion of the transfer objective body just entering the liquid relative to the liquid surface may be set preferably from 10xc2x0 through 170xc2x0.
If the liquid entrance angle is less than 10xc2x0, the air will be easily involved while if the liquid entrance angle is more than 170xc2x0, the transfer film will be poorly wrapped whereby the pattern discontinuation undesirably tends to occur.
The liquid entrance angle of 10xc2x0 or more than to less than 90xc2x0 implies that the transfer face portion of the transfer objective body enters the liquid while it is inclined in the same direction as the direction of feeding the transfer film, the liquid entrance angle of over 90xc2x0 to 170xc2x0 implies that the transfer face portion of the transfer objective body enters the liquid while it is inclined in the direction reverse to the direction of feeding the transfer film and the liquid entrance angle of 90xc2x0 implies that the transfer face portion of the transfer objective body enters the liquid at a right angle relative to the liquid surface.
In case that the transfer face portion of the transfer objective body extends not only over the front face thereof, but also along the edge of the back face succeeding the front face of the transfer objective body, it is required to enter the liquid so that the transfer film is wrapped around the transfer back face (the back edge) as already described. Also in this case, the liquid entrance angle should be set from 10xc2x0 through 170xc2x0.
As the transfer face of the transfer objective body has a dent in the condition that the transfer objective body enters the liquid in an inclined manner at the normal entrance angle while the transfer face including the dent is closed relative to the liquid surface, the air pocket will be formed between the face portion including the dent and the transfer film. Therefore, in this case, the transfer objective body is required to enter the liquid while the transfer face portion is directed upwardly relative to the liquid surface so that the transfer face portion corresponding to the edge of the dent (a border portion) is never closed. In this manner, no air remains in the dent and as a result, the print pattern is prevented from being not adhered to the transfer face of the transfer objective body due to the formation of the air pocket.
Preferably, the transfer objective body may have a plurality of sections divided on the just entering surface portion thereof along the longitudinal direction. There may be set each of the sections for every different surface configuration such as every portion having a protrusion on the side of the transfer film, every portion having a dent thereon or every portion having a protrusion or a dent, but having variation in the radius of curvature, for example. The liquid entrance conditions such as the liquid entrance pose (including the liquid entrance angle), the liquid entrance velocity and so on are set for every section in accordance with the surface configuration of every section.
The method of the invention may be accomplished by previously storing the liquid entrance conditions such as a pose mode in which the transfer objective body enters the liquid so that the transfer objective body follows the transfer film while the transfer face portion of the transfer objective body is developed on the transfer film in a plane manner, a substantially constant liquid contact position where the surface portion of the transfer objective body contacts the liquid if necessary (in case of the transfer film feeding system), the liquid entrance velocity, which are set for every surface portion such as the section of the transfer objective body) just entering the liquid and conveying the transfer objective body while the liquid entrance pose and so on are controlled for every the surface portion of the transfer objective body in accordance with the previously stored data.
The pose mode when the transfer objective body enters the liquid may be preferably set for every section and therefore transfer objective body conveyance control means stores the pose mode different for every section and controls the conveyance pose of the transfer objective body based on the pose mode set for every section just entering the liquid within the transfer bath.
Secondly, this invention pertains to a liquid pressure transfer apparatus comprising a transfer bath to float a transfer film having a predetermined print pattern and transfer the print pattern on a transfer objective body while a liquid pressure is applied to the transfer objective body and transfer objective conveyance means to convey the transfer objective body so that the surface portions of the transfer objective body sequentially enter the liquid in a manner faced to the transfer film within the transfer bath whereby the print pattern on the transfer film is transferred onto the transfer objective body using the liquid pressure and then move the pattern-transferred surface portions of the transfer objective body away from the liquid surface within the transfer bath whereby the transfer objective body is sequentially taken out of the transfer bath.
The apparatus of the invention is characterized by including transfer objective body conveyance control means to control a pose of the transfer objective body so that the transfer face of the transfer objective body enters the liquid while the transfer objective body follows the transfer film so that the transfer face of the transfer objective body is developed onto the surface of the transfer film within the transfer bath in a plane manner.
In the apparatus of the invention, the transfer objective body conveyance control means is so constructed as to control the entrance of the transfer objective body into the liquid by the aforementioned method. This transfer objective body conveyance control means conveys the transfer objective body while controlling the pose of the transfer objective body so that the transfer objective body enters the liquid while it is contacting the transfer film with the pose of the transfer objective body rolling system or the transfer objective body oblique lowering system.
In the transfer objective body conveyance control means, the liquid entrance conditions of the transfer objective body may be preferably set for each of a plurality of sections into which the transfer objective body is divided along the liquid entrance direction. The sections may be individually formed based on the portions which have a surface configuration largely different from each other and the central line of each of the sections should be set while right and left three-dimensional configurations of each of the transfer objective body sections are considered so that they are balanced in a transverse direction.
The transfer objective body conveyance control means previously stores the liquid entrance conditions such as the pose mode (including the liquid entrance angle) set so that every transfer face portion of the transfer objective body enters the liquid while it is developed on the transfer film in a plane manner, the predetermined liquid entrance velocity set for every transfer face portion, a liquid contact position (in case of the transfer film feeding system) set for every transfer face portion and so on and controls the poses of the transfer objective body and other conditions on the conveyance of the transfer objective body based on the data previously stored in this manner.
As already described, the liquid entrance conditions including the pose mode and so on when the transfer objective body enters the liquid may be preferably set for every section and therefore the transfer objective body conveyance control means stores the pose mode different for every section and controls the conveyance pose of the transfer objective body based on the pose mode set for every section just entering the liquid within the transfer bath.
Since the transfer objective body has the liquid entrance pose varied whenever the end of each of the sections reaches the liquid, as the transfer objective body is controlled based on the variation in the liquid entrance pose, the transfer objective body will be conveyed in a stepped manner because it is subject to abrupt variation in the liquid entrance pose and so on whenever the liquid entrance of the transfer objective body changed from one section to another section. In order to avoid this, the transfer objective body conveyance control means preferably controls the conveyance of the transfer objective body so that the liquid entrance pose and so on vary in a smooth manner by applying a smoothing command to the transfer objective body conveyance control means before and after the sections are switched.
In the apparatus of the invention, the transfer objective body conveyance means may preferably comprise a plurality of carrying-in transfer objective body conveyance units disposed in a manner spaced to each other in a position adjacent to a liquid contact position of the transfer bath where the transfer object body contacts the liquid and at least one carrying-out transfer objective body conveyance unit disposed in a position adjacent to a transfer objective body taking out position of the transfer bath.
Thirdly, this invention pertains to a liquid pressure pattern-transferred article which is characterized by being formed by transferring the print pattern onto the transfer objective body by the aforementioned method.
The transfer objective body to which the invention may be applied is an article of which the liquid entrance face contacts the surface of the transfer film with the contact area remarkably different from each other if it enters the liquid with the same pose maintained and there are a fender, a door, a bonnet, a bumper of a small-sized car and so on as such an article. It should be noted that such an article may include one used in various fields other than the outer panels of the car.
In this manner, as the pose of the transfer objective body is controlled so that the face (transfer face) of the transfer objective body onto which the print pattern should be transferred enters the liquid while it follows the transfer film so that the transfer face is developed on the surface of the transfer film in the plane manner, in case that the transfer objective body is a large-sized one such as the car panel including the fender, the door or the bonnet of the small-sized car, for example, which has a large radius of curvature, a large area of the curved portion and large areas of adjacent portions on both sides of the curved portion even though it has a small value of angle variation of the curved portion, the transfer objective body enters the liquid while all the surface portions of the transfer objective body contact the surface of the transfer film with the substantially identical contact area in accordance with variation in the surface configuration of the transfer objective body so that the print pattern on the transfer film is transferred onto the surface of the transfer objective body. This prevents the print pattern which should be transferred from being extended and thinned in its color. This allows the print pattern to be satisfactorily attached all over the surface portions of the transfer objective body and therefore the pattern transferred onto the transfer objective body is maintained uniformly and an intended expression of design can be obtained on the transfer objective body.
A movement of the transfer objective body for contacting the transfer film while it follows the transfer film so as to be developed thereon can be easily accomplished by rolling the transfer face of the transfer objective body on the surface of the transfer film or lowering the transfer objective body obliquely downward relative to the surface of the transfer film.
Even though the transfer face of the transfer objective body has a dent, the transfer objective body can enter the liquid while the transfer face thereof is opened when the edge of the dent enters the liquid. This can effectively avoid such an air pocket as obstructs the print pattern from being closely attached to the transfer objective body.
As the liquid entrance conditions such as the liquid entrance pose (including the liquid entrance angle), the liquid entrance position, the liquid entrance velocity or the like are set for each of a plurality of sections into which the transfer objective body is divided for the portions which have a surface configuration largely different from each other, the conditions necessary for entering the liquid in the same conditions as the transfer face of the transfer objective body is developed on the surface of the transfer film in the plane manner can be easily obtained and as a result, the liquid entrance of the transfer objective body can be easily controlled.
In the liquid pressure transfer technique according to the transfer film feeding system, as the transfer face of the transfer objective body is so set to enter the liquid at the substantially identical position (the liquid entrance position) in the direction in which the liquid flows, the transfer objective body immersed into the liquid at the position where the ink forming the print pattern on the transfer film always has a uniform degree of re-tackiness and a uniform degree of swell. This serves to improve the transfer characteristics together with the principle that the surface of the transfer objective body enters the liquid while it contacts the transfer film in a plane manner.
Furthermore, as the liquid entrance conditions such as the pose modes (including the liquid entrance angle) set so that every transfer face portion of the transfer objective body enters the liquid while it is developed on the transfer film in the plane manner, the substantially constant liquid entrance position where the face portion of the transfer objective body enters the liquid and the predetermined liquid entrance velocity set for every transfer face portion (the two latters thereof set only in case of the transfer film feeding system) are previously stored and as the liquid entrance conditions such as the poses of the transfer objective body on the conveyance of the transfer objective body are controlled in accordance with the previously stored data, the operation of transferring the print pattern on various transfer objective bodies can be promptly made by changing record medium having the liquid entrance conditions previously stored for every kind of the transfer objective body or by switching the areas in which the data are written.
The data written areas may be switched on an identification which can be made by detecting an indication such as hole, notch or the like provided in a holder for the transfer objective body by a suitable detector such as a proximity switch, a limit switch or an optical switch (sensor) so that the kind of the transfer objective bodies (articles) on the holder therefor is recognized.
In the apparatus of the invention, as the transfer objective body conveyance means comprises the plurality of carrying-in transfer objective body conveyance units disposed in a manner spaced to each other in the position adjacent to the transfer objective body liquid entrance position of the transfer bath and at least one carrying-out transfer objective body conveyance unit disposed in the position adjacent to the transfer objective body taking out position of the transfer bath, the plurality of the carrying-in transfer objective body conveyance units can be alternately used for sequentially carrying in each one of the transfer objective bodies to the transfer objective body liquid entrance area and deliver these transfer objective bodies to the carrying-out transfer objective body conveyance unit at the transfer objective body liquid take-off area.
Thus, one of the carrying-in transfer objective body conveyance units which previously carries in the transfer objective body can be rapidly returned to the carrying-in start position while another carrying-in transfer objective body conveyance unit is carrying in the next transfer objective body and therefore, the number of the transfer objective bodies onto which the print pattern should be transferred per unit time can increase whereby the liquid pressure transfer operation can be more effectively made.
In particular, since the moving velocity of the carrying-in transfer objective body conveyance units is relatively later after the transfer objective body enters the liquid until it leaves the liquid (while it is immersed into the liquid), if the transfer operation would be made for many transfer objective bodies using only one carrying-in transfer objective body conveyance unit, it will take much time that the single transfer objective body conveyance unit carries in the transfer objective body and delivers the pattern-transferred objective body to the carrying-out transfer objective body conveyance unit. Thus, the transfer operation for the adjacent transfer objective bodies cannot be over in short time. However, with the plurality of carrying-in transfer objective body conveyance units used, while one of the carrying-in transfer objective body conveyance units is carrying in the transfer objective body, the other carrying-in transfer objective body conveyance unit can be rapidly returned to the carrying-in start position. Therefore, the next transfer objective body can be soon carried in to the transfer position succeeding the former transfer objective body. Thus, it will be noted that the print pattern can be more effectively transferred onto more transfer objective bodies with a relatively shorter space by the two carrying-in transfer objective body conveyance units.
As the liquid pressure transferred articles are produced with the liquid entrance surface portion of the transfer objective body immersed into the liquid with such a pose as the surface portion is developed on the surface of the transfer film in the plane manner, it can have a good appearance without any obscure pattern transferred even though it has a large sized and complicated configuration.